Portable oxygen system



FIG. 1 is a front perspective view of a portable oxygen system showing my new design;

FIG. 2 is a right end elevational view thereof;

FIG. 3 is a left end elevational view thereof;

FIG. 4 is a top plan view thereof; and,

FIG. 5 is a front elevational view thereof.

The bottom and rear of the article are substantially plain and unornamented. 

The ornamental design for a portable oxygen system, as shown. 